312 ILLINOIS ACADEMY OF SCIENCE 
If we compute the mean for all the individuals’ (both parents 
and offspring) for these three isolations we get 1.544 mm. as 
the mean for the whole line. Above this mean we find 48 of 
the 55 parents, and below it only 7 parents. This shows how 
severe was the test of selection in these experiments. Further, 
the mean of all the parents selected is found to be 1.728 mm. 
which is 0.184 mm. greater than the mean for the line, or about 
12 per cent greater in length than the average length of all 
individuals of the three sublines. In Table IV we find cor- 
relations given for the size of these 55 parents and their off- 
spring. 
The results observed in Table IV appear to give us a con- 
siderable correlation between parents and offspring. But, 
knowing as I do the conditions of the experiment, I would at- 
tach little significance to this table as far as indicating any in- 
herited differences between parent and offspring. We find in 
the three lowest parental classes containing any individuals, 
1.25-1.29, 1.40-1.44, and 1.50-1.54, that the modes for the 
offspring as well as the means are unusually low, except for 
the one offspring in the class 1.25-1.29 which can be disregard- 
ed. Certainly this shows correlation, our critics say. Yes it 
does, but not necessarily inheritance. An examination of my 
notes shows that three of the seven parents included in this 
class were produced while feeding on older wheat plants than 
usual, as also did their offspring. It was shown clearly in my 
experiments that older wheat plants caused a diminution of 
the size of the individuals. Two of the remaining parents as 
well as their offspring were produced under exceptionally low 
temperature, in fact the temperature was many degrees lower 
than usual. These conditions of course would affect both 
parent and offspring. The parent going in the highest class, 
2.15-2.19, is of special interest. This individual is four classes 
ahead of the next longest parents which go in the 1.95-1.99 
class. Certainly this must be an example of mutation! The 
mean of its offspring also is far above any other mean. But 
let us examine the case farther. The parent of this fraternity, 
measured 2.15 mm., yet this great size was not permanently 
inherited, for the mean of its grandchildren came down to 
1. For the actual measurements of these individuals, of which there were 
543, the reader is referred to the previous paper by the writer (Ewing, 1916). The 
measurements of two individuals were lost, and in a few cases measurements were 
mot made of abnormal ones or those that were seriously distorted. 
